Stormwater Management

Total Page:16

File Type:pdf, Size:1020Kb

Stormwater Management THE COMPLETE GUIDE TO Stormwater Management 2 | THE COMPLETE GUIDE TO STORMWATER MANAGEMENT Introduction Welcome consultants, civil and application engineers, planners and users of stormwater systems around the world. We have created this detailed guide to outline the many ways in which we can help you resolve some of the most challenging scenarios related to stormwater management, flood prevention and relief. In our view this is achieved through smart pump station design, innovative solutions, state of the art equipment and capacity utilization with network optimization. For more than 60 years, our engineers have resolved issues ranging from compact, cost-efficient pump sump station design, correct pumping duty conditions and monitoring and control requirement, to data collection and analysis, as well as tailor-made stormwater projects. Some examples of their work are highlighted throughout this document. The objective of sharing all this information is to give you answers and guidance into how to maximize a community’s capacity to manage stormwater. This is our way to contribute to eliminate the danger to people, property and the environment that severe stormwater events can cause. We hope you find this resource useful and welcome your feedback. Comments and inquiries can be sent through your local Xylem sales engineer or contact information on our website: www.xylem.com/en-us/support/contact-us/ Tomas Brannemo President, Transport and Treatment, Xylem. 3 Table of Contents 2 TABLE OF CONTENTS 04 4 | THE COMPLETE GUIDE TO STORMWATER MANAGEMENT Stormwater Management Trends and Challenges Over the last 50 years, the global urban population has grown from 1.2 to 4.5 billion. 6 | THE COMPLETE GUIDE TO STORMWATER MANAGEMENT Half a century from now, our global urban population is projected to reach seven billion.1,2 In the meantime, changes to global climate patterns are causing more intense rainfall and pronounced droughts. Although modern cities have the necessary infrastructure in place to control the resulting stormwater, often the systems they have in place are outdated and not designed for a long service life. Many cities continue to operate conveyance structures, which contain parts that are multiple decades old; implemented before planners became aware of the issues of climate change and rapid urban expansion. Today, urban growth and increasingly intense rainfall events cause these systems to be overloaded, resulting in frequent and serious flooding. Moving forward, stormwater control infrastructure will be required to live up to the challenges of population growth and climate change. It will also need to function properly in a world in which urban densification will make less space available for the implementation of stormwater control solutions. From an engineering perspective, stormwater assets will need to be considered in a broader context. Copenhagen is a prime example of this. In the last decade, Denmark’s capital city and home to over 1.2 million people has suffered flood damage in excess of one billion Euros.3 As a result, the city brought together specialists from many different disciplines to develop a 20-year plan aimed at improving water resilience. Copenhagen’s plan integrates a wide variety of solutions for flood protection and recreational stormwater usage; it also includes measures such as building blue and green streets and parks, constructing rain gardens and using roads as open waterways for extreme stormwater relief. The infrastructure needed for urban stormwater control is significant in terms of both scale and expense, and it can’t be replaced on a whim. It is built for a century of intended service life and requires long-term planning. Meanwhile, continuous upgrading and refining of this infrastructure will be critical to solving acute issues on the fly without undermining long-term planning goals. This requires an in-depth understanding of every aspect of your stormwater control system, from the technical details of complex system interactions, to knowledge of the socio-economic and public perception implications. The only way for modern cities to meet present and future water productivity, water quality and water resilience needs is to implement the best available technologies in a resilient, long-term planning context. Jes Vollertsen Professor, Institut for Byggeri og Anlæg Thomas Manns Vej 23 Lokale: 1-258 9220 Aalborg Ø, DK 1 https://esa.un.org/unpd/wup/Publications/Files/WUP2014-Report.pdf 2 https://esa.un.org/unpd/wpp/Publications/Files/WPP2017_KeyFindings.pdf 3 http://www.forsikringogpension.dk 7 Defining Stormwater Management 8 | THE COMPLETE GUIDE TO STORMWATER MANAGEMENT In rural environments, a majority of rainfall infiltrates into the ground, while some excess slowly forms runoff streams or watercourses. In cities and other urban spaces, rainfall collects rapidly and becomes runoff as the impervious surfaces of streets, paved areas and rooftops prevent it from infiltrating into the ground. Rainfall events also impact bodies of water, such as rivers and lakes, causing their water levels to rise periodically. Since many urban centers are built in the vicinity of these bodies of water, measures must be taken to prevent them from flooding. Stormwater management refers to the way in which these flows, and their potential pollutants (sand, chlorides, organic matter and even large objects), can best be managed using a wide range of solutions. It covers a broad spectrum of activities, from planning and measurement, to monitoring and control, as well as pumping and treatment. It includes infrastructure such as gutters, conduits and trenches, in addition to detention tanks, large and small pump stations and treatment plants. Continue reading to discover what successful stormwater management looks like in urban spaces, and how the right solution can help you effectively improve water resilience in any environment. 9 Part One Examining Stormwater Management in Dense Urban Environments Water is a vital resource that is deeply integrated into urban life. 10 | THE COMPLETE GUIDE TO STORMWATER MANAGEMENT In spite of this, urbanization can radically change the flow of water and create a range of adverse effects, such as frequent, severe floods and changes in water quality. Around the world, urban water managers are constantly dealing with these issues, as well as other new and unprecedented challenges posed by stormwater events. Investing in an efficient stormwater collection system, applying best management practices (BMPs) and implementing the right pumping storage and treatment infrastructures can help these individuals protect their communities from evolving natural hazards. Sponge Cities To accommodate rapid urban migration and development, some countries are turning to sponge city initiatives. The sponge city concept proposes the implementation of sustainable and ecological flood control methods with minimal footprint and energy consumption. It employs ecological principles, landscape architecture approaches and key techniques of infiltration, pumping, storage, purification, utilization and discharge. These techniques are applied through best management practices (BMPs) and green stormwater infrastructures (GSI) with low impact, as decided by each municipality. One of the most ambitious sponge city programs is being developed in China, which launched pilot cases in 16 different cities in 2015 and plans to roll the scheme out nationally. To assist in sponge city development, the Chinese government provides annual funding to qualified cities and municipalities across provinces.4 By 2020, China hopes that 80% of its urban areas will be able to absorb and re-use at least 70% of rainwater.5 4 http://chinawaterrisk.org/about/ 11 5 http://www.cnn.com/2017/09/17/asia/china-sponge-cities/index.html Part One Examining Stormwater Management in Dense Urban Environments A | SELECTING THE RIGHT STORMWATER CONTROL SOLUTION COMBINED SEWER SYSTEM VERSUS SEPARATE SEWER SYSTEM Begin your evaluation of urban stormwater control solutions by identifying which type of sewer system your community has in place. Sewer systems can either be combined or separate, and each type comes with different risks and benefits. Combined sewers, for example, are designed to collect both wastewater and stormwater through a single pipe system. Separate sewers consist of two isolated pipe systems–one for wastewater and another for stormwater. In a separate system, stormwater is conveyed to a designated outfall and commonly discharged directly into the receiving water. In a combined system, the flow of stormwater and wastewater is directed to a treatment plant prior to being released to natural sources. The figures below show the potentially severe environmental consequences of a combined system overflow. In the event of heavy precipitation or snow meltdown, large quantities of mixed and untreated stormwater and wastewater may be released into nearby bodies of water. Use a comprehensive review of your community’s current sewer system as the foundation for making decisions regarding efficient stormwater collection, detention or retention, transport to a treatment plant and release. Combined Sewer System Combined Sewer Overflow (CSS) (CSO) 12 | SELECTING THE RIGHT STORMWATER CONTROL SOLUTION STORMWATER DISINFECTION Rain events can cause combined sewer overflows (CSOs) when conveyance systems or treatment plants are overwhelmed by stormwater. In addition to polluted runoff, CSOs contain pollutants and pathogens from raw sewage that pose
Recommended publications
  • A Model-Based Assessment of Infiltration and Inflow in the Scope of Controlling Separate Sanitary Overflows at Pumping Stations Olivier Raynaud, C
    A model-based assessment of infiltration and inflow in the scope of controlling separate sanitary overflows at pumping stations Olivier Raynaud, C. Joannis, Franck Schoefs, F. Billard To cite this version: Olivier Raynaud, C. Joannis, Franck Schoefs, F. Billard. A model-based assessment of infiltration and inflow in the scope of controlling separate sanitary overflows at pumping stations. 11thInter- national Conference on Urban Drainage (ICUD 08), 2008, Edinburgh (Sotland), United Kingdom. hal-01007760 HAL Id: hal-01007760 https://hal.archives-ouvertes.fr/hal-01007760 Submitted on 18 Nov 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A model-based assessment of infiltration and inflow in the scope of controlling separate sanitary overflows at pumping stations O. Raynaud1, C. Joannis1, F. Schoefs2, F. Billard3 1Laboratoire Central des Ponts et Chaussées, Route de Bouaye, B.P 4129, 44 341 Bouguenais Cedex, France 2Institut de Recherche en Génie Civil et Mécanique (Gém), Nantes, France 3Nantes Métropole, Direction de l’assainissement, Nantes, France ABSTRACT Infiltration & Inflow (I&I) are a major cause for separate sanitary sewers overflows (SSOs). A proper planning of actions for controlling SSOs needs a precise quantification of these events, as well as an identification of the respective contributions of infiltration into sewer and inappropriate connection of runoff water to sanitary sewers.
    [Show full text]
  • Dhamori Village Development Plan
    This presentation premiered at WaterSmart Innovations watersmartinnovations.com Translating Historical Water Wisdom to Contemporary Challenges Leslie A. Johnson, 2018 MLA Capstone Chair: Professor John Koepke Department of Landscape Architecture, University of Minnesota Project Advisor: Alpa Nawre, University of Florida Agenda 1. Contemporary Issues in India & the Relationship to Traditional Water Management 2. Site Visit to Dhamori, India & Project Background 3. Water Wisdom: Capstone Research & Design 4. Lessons Learned & Broader Applications Image Credit: Dhamori Village - Leslie A. Johnson Part I. Contemporary Issues in India & the Relationship to Traditional Water Management India today faces a wide variety of social, environmental, and cultural issues related to water issues. • Conflicts between domestic and productive water use • Farmer suicides in rural communities Image Credit: Maharashtra Farmer during Drought - Jagadeesh NV, European Press Photo Agency / Relocated Workers - “Drought in Maharashtra,” Mumbai Mirror / Farmer Suicides - India You, 2011 Part I. Contemporary Issues in India & the Relationship to Traditional Water Management • Threats to food security • Seasonal migration to cities • During the monsoon, there can be too much water, but during the dry season, there can be too little Challenges stem from water mismanagement as much, or more so, as from water scarcity. Yet India has a rich history of water conservation strategies, so how is it that these current issues came to be? Image Credit: In wait for water - Mumbai Mirror / Stepwell – Atlas Obscura Part I. Contemporary Issues in India & the Relationship to Traditional Water Management What is ”traditional water management?” Broadly, water systems present prior to industrialization, specifically those systems derived from the vernacular of their landscapes and needs of a particular group of people.
    [Show full text]
  • Full Document (Pdf 1196
    Final Report GeoEngineers On-Call Agreement Y-7717 Task Order AU AN APPROACH FOR ESTIMATING INFILTRATION RATES FOR STORMWATER INFILTRATION DRY WELLS by Joel Massmann, Ph.D., P.E. Washington State Department of Transportation Technical Monitor Glorilyn Maw Washington State Transportation Commission Department of Transportation and in cooperation with U.S. Department of Transportation Federal Highway Administration April 2004 TECHNICAL REPORT STANDARD TITLE PAGE 1. REPORT NO. 2. GOVERNMENT ACCESSION NO. 3. RECIPIENT'S CATALOG NO. WA-RD 589.1 4. TITLE AND SUBTITLE 5. REPORT DATE AN APPROACH FOR ESTIMATING INFILTRATION April 2004 RATES FOR STORMWATER INFILTRATION DRY WELLS 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT NO. Joel Massmann, Ph.D., P.E. 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NO. 11. CONTRACT OR GRANT NO. Agreement Y7717, Task AU 12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED Research Office Final Research Report Washington State Department of Transportation Transportation Building, MS 47372 Olympia, Washington 98504-7372 14. SPONSORING AGENCY CODE Keith Anderson, Project Manager, 360-709-5405 15. SUPPLEMENTARY NOTES This study was conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration. 16. ABSTRACT This report describes an approach for estimating infiltration rates for dry wells that are constructed using standard configurations developed by the Washington State Department of Transportation. The approach was developed recognizing that the performance of these dry wells depends upon a combination of subsurface geology, groundwater conditions, and dry well geometry. The report focuses on dry wells located in unconsolidated geologic materials.
    [Show full text]
  • Graham Park Sewage Pumping Station and Force Main Improvement Project
    Graham Park Sewage Pumping Station and Force Main Improvements Project Number: SPS112 Project Summary Project Commencement: Anticipated Start of Construction - Spring 2019 Project Description: Replacement of an existing antiquated Sewage Pumping Station (SPS) and force main (FM), and raise the SPS control building and equipment above the 100-year flood plain elevation. Scope of Work: This project will consist of installing a new submersible SPS with new controls, motors, emergency generator, by-pass connection on FM, and new flow metering equipment. The proposed pump control enclosure will be about 12’ in height and will be approximately 7’ by 13’ in size consisting of a faux-brick façade. The facility will be enclosed with an 8’ high chain-link fence with barbed-wire and locked for security. Additionally, the project will provide emergency backup supply and protect pump station facilities from storm surge flooding. Project benefits: The project will improve service reliability, safety conditions, and provide permanent back-up power. Project impact on residents/customers Noise associated with construction. Construction trucks accessing the SPS. Daily cleanup during construction to remove dust and dirt. Potential impact on traffic: Our standard roadway and traffic matters are outlined below. The Construction Contractor will be required to comply with Department of Environmental Quality (DEQ) Erosion and Sediment Control requirements to ensure all construction traffic does not track dirt on roads. The Service Authority will include in the construction contract a provision for fees to be assessed if the Construction Contractor does not comply with these requirements. Regular project updates to the impact of traffic will be listed on the website Graham Park Project.
    [Show full text]
  • Pump Station Design Guidelines – Second Edition
    Pump Station Design Guidelines – Second Edition Jensen Engineered Systems 825 Steneri Way Sparks, NV 89431 For design assistance call (855)468-5600 ©2012 Jensen Precast JensenEngineeredSystems.com TABLE OF CONTENTS INTRODUCTION ............................................................................................................................................................. 3 PURPOSE OF THIS GUIDE ........................................................................................................................................... 3 OVERVIEW OF A TYPICAL JES SUBMERSIBLE LIFT STATION ....................................................................................... 3 DESIGN PROCESS ....................................................................................................................................................... 3 BASIC PUMP SELECTION ............................................................................................................................................... 5 THE SYSTEM CURVE ................................................................................................................................................... 5 STATIC LOSSES....................................................................................................................................................... 5 FRICTION LOSSES .................................................................................................................................................. 6 TOTAL DYNAMIC HEAD ........................................................................................................................................
    [Show full text]
  • Sanitary Sewer Overflow Corrective Action Plan/Engineering Report
    FAYETTEVILLE PUBLIC UTILITIES WATER AND SEWER DEPARTMENT SANITARY SEWER OVERFLOW CORRECTIVE ACTION PLAN ENGINEERING REPORT 408 College Street, West Fayetteville, TN 37334 (931)433-1522 CONSOLIDATED TECHNOLOGIES, INC. Engineers in Water and Earth Sciences Nashville, Tennessee TABLE OF CONTENTS Page 1 INTRODUCTION 1.1 Background and Purpose Scope 2 EXISTING SEWER SYSTEM 2.1 Gravity Sewers 2.2 Pumping Stations 2.2 Wastewater Treatment Plant 2.3 3 EXISTING WASTEWATER TREATMENT PLANT 3.1 Plant Design Data 3.2 Influent Pump Station 3.2 Headworks 3.2 Aeration Basins 3.3 Secondary Clarifiers 3.3 Return Sludge Pump Station 3.3 Disinfection Facilities 3.4 Sludge Digestion and Holding Facilities 3.4 Sludge Disposal Site 3.4 Drying Beds 3.5 Staff 3.5 Operating Review 3.5 4 PREVIOUS SEWER SYSTEM OVERFLOWS (SSO’s) 4.1 Existing Problems 4.2 5 EXISTING AND FUTURE SEWER FLOWS 5.1 Flow Measurement Data 5.2 Projection of Future Flows 5.4 6 PLAN FOR I/I REDUCTION AND ELIMINATION OF SSO’s 6.1 New Construction Sewer System Rehabilitation 7 RECOMMENDED CAPITAL IMPROVEMENTS 7.1 Projects Currently Under Design/Construction 7.2 Projects Planned for Construction 7.3 Project Schedule 7.6 Project Maps LIST OF TABLES 2.1 Pump Station Information 2.3 3.1 Discharge Monitoring Reports Summary 3.5 4.1 Overflows/Bypasses 4.2 5.1 Flow Monitoring Sites 5.2 TABLE OF CONTENTS (Continued) LIST OF TABLES (Continued) Page 5.2 Historical Sewer and Water Customers 5.4 5.3 Future Flow Projections 5.5 7.1 Project Schedule 7.6 Follows Page LIST OF FIGURES 2.1 General Map 2.2 3.1 Site
    [Show full text]
  • Maintaining Your Detention Basin: a Guidebook for Private Owners in Clermont County
    Maintaining Your Detention Basin: A Guidebook for Private Owners in Clermont County A well maintained detention basin BASINS Your detention basin is a storm water best management practice (BMP) designed to tempo- INTRODUCTION rarily capture and hold storm water runoff during periods of heavy rain, and slowly release this flow over a period of one or two days so it minimizes flooding and streambank erosion problems downstream. They also help remove sediments from storm water runoff, which helps improve the quality of local streams. Like most other things, a detention basin may not function properly or it may fail prematurely if not properly maintained. Once a detention basin fails, it is often very expensive to correct. Many detention basins are located on private property, including parcels of land owned and maintained by a homeowners association (HOA). Local governments do not have the au- thority to maintain components of the storm sewer system on private property, including detention basins. Rather, these are the responsibility of the lot owner to maintain. Whether you are an individual property owner, a homeowner’s association representative, or a residential/commercial property manager, this Guidebook will help answer questions and provide you with instructions for basin maintenance activities. Routine maintenance will prolong the life of your detention basin, improve its appearance, help prevent flooding and property damage, and enhance local streams and lakes. WHAT ARE DETENTION BASINS AND WHY ARE THEY IMPORTANT? When land is altered to build homes and other developments, the natural system of trees and plants over relatively spongy soil is replaced with harder surfaces like sidewalks, streets, decks, roofs, driveways and even lawns over compacted soils.
    [Show full text]
  • Single Family Residential Stormwater Management Plan Dry Well (Infiltration) Construction Inspections
    Single Family Residential Stormwater Management Plan DRY WELL (INFILTRATION) Definition : A dry well is an excavated pit filled with gravel and sand that provides temporary storage of runoff from roofs and allows for infiltration of that runoff over a 48 hour period. Constraints : • Dry wells should not be used in areas where their operation may create a risk for basement flooding, interfere with septic sewage disposal systems, or cause downslope seepage problems • May not be installed on slopes greater than 20% • Drainage area to each dry well shall not exceed 1000 square feet • Dry wells may not be used in HSG D or if the infiltration rate of the soil is less than 0.27 inches per hour • Dry wells are intended to capture rooftop runoff only Design Guidance: • Dry wells must be installed in accordance with the attached detail • Dry wells should not intercept water table, bedrock, fragipan or other confining layer • Dry wells must be located down gradient of building structures and set back at least 10 feet from buildings, 50 feet from water supply wells and 25 feet from septic systems • Dry wells must be set back at least 50 feet from fill slopes of 25% or steeper • Soils will be evaluated during excavation by ASCD representative to evaluate soil suitability assumed in original design which may alter type of practice to be constructed Installation: • Minimize compaction of dry well bottom and sidewalls • Collection pipes from downspouts shall be 4”-6” PVC installed at min. slope of 1% • The bottom of the dry well excavation should be
    [Show full text]
  • Sanitary Sewer & Pumping Station Manual
    SANITARY SEWER AND PUMPING STATION MANUAL FOR SPRINGFIELD WATER AND SEWER COMMISSION Last Revised: _July 20, 2017______________ Page 1 TABLE OF CONTENTS Title Section Number General 1 Drawing Requirements 2 Construction Procedures 3 Flow Determination 4 Computer Modeling 5 Sanitary Sewers 6 Pump Stations 7 Appendices A – Checklist B – Construction Specifications C – Standard Drawings Page 2 SECTION 1 – GENERAL 1.1 General................................................................ 4 1.2 Purpose................................................................ 4 1.3 Structure of the Manual................................................ 4 1.4 Definitions............................................................ 4 1.5 References............................................................. 9 Page 3 1.1 General The Sanitary Sewer and Pumping Station Manual is for the design and construction of infrastructure. The specific subjects of these manuals are: • Procedures Manual for Infrastructure Development • Sanitary Sewer and Pumping Station • Structures • Geotechnical • Construction Inspection 1.2 Purpose The purpose of this manual is to provide information regarding design and construction requirements for sanitary sewers, pumping stations, and force mains in Springfield, Kentucky. The goal is to provide uniform design and construction standards. The end result will be public infrastructure that is cost effective and maintainable by the Springfield Water and Sewer Commission (SWSC)in the long term. 1.3 Structure of the Manual The manual
    [Show full text]
  • Chapter 23: Detention Basin Standards
    CHAPTER 23: DETENTION BASIN STANDARDS 23.00 Introduction and Goals 23.01 Administration 23.02 Standards 23.03 Standard Attachments 23.1 City of Champaign Manual of Practice March 2002 Chapter 23: Detention Basin Standards 23.00 INTRODUCTION AND GOALS A. The purpose of this chapter is to explain the City’s policy regarding the ownership, design, construction, and maintenance responsibility for detention basins. Detention basins are used to collect and hold stormwater runoff for a period of time to compensate for increases in stormwater runoff caused by reduced ground surface perviousness due to activities such as paving or building construction. B. Detention basins historically range in size from backyard detention provided by swales, to large regional detention ponds. Detention basins may be wet or dry bottomed. Residential backyard or sideyard single lot detention is not allowed. Construction of detention for individual lots of less than 5 acres is not recommended; alternate methods such as payment in lieu of detention or one basin for the entire subdivision or development are preferred. 23.01 ADMINISTRATION A. This chapter applies to detention basins within the City limits and the 1-1/2 mile extra territorial jurisdiction. B. Detention basin construction is required for certain conditions by the City of Champaign Stormwater Management Regulations. C. Detention basin design shall be reviewed by the City of Champaign through either of the following: 1. Subdivision plan review 2. Grading and drainage plan review 3. Alternate construction plan review (typically public improvements) 23.02 STANDARDS The following standards apply to detention basins: A. Referenced Standards: Design standards for detention basin design and construction shall comply with the provisions of the following, unless otherwise stated by this manual.
    [Show full text]
  • Evaluation of Sanitary Sewer Overflows and Unpermitted Discharges Associated with Hurricanes Hermine & Matthew
    EVALUATION OF SANITARY SEWER OVERFLOWS AND UNPERMITTED DISCHARGES ASSOCIATED WITH HURRICANES HERMINE & MATTHEW JANUARY 6, 2017 THIS PAGE WAS LEFT BLANK INTENTIONALLY EVALUATION OF SANITARY SEWER OVERFLOWS AND UNPERMITTED DISCHARGES ASSOCIATED WITH HURRICANES HERMINE & MATTHEW Financial Project No.: January 6, 2017 PR9792143-V2 RS&H No.: 302-0032-000 Prepared by RS&H, Inc. at the direction of the Florida Department of Environmental Protection ii THIS PAGE WAS LEFT BLANK INTENTIONALLY TABLE OF CONTENTS Chapter 1 INTRODUCTION ............................................................................................................................................................... 1 1.1 SCOPE OF THE EVALUATIONS..................................................................................................................................... 1 1.2 METHODOLOGY ............................................................................................................................................................... 2 1.3 DOCUMENT OVERVIEW ................................................................................................................................................ 2 Chapter 2 STORMWATER AND WATER LEVEL ANALYSIS .................................................................................................... 3 2.1 PRECIPITATION DATA .................................................................................................................................................... 3 2.1.1 Hurricane Hermine ...................................................................................................................................................
    [Show full text]
  • Infiltration Trench & Soakaway
    An Infiltration Trench System includes an inlet pipe or water source, catch basin sump, perforated DESIGN PRINCIPLES distribution pipe, infiltration trench and overflow to the storm drainage system. ■ Infiltration Trench System: A Soakaway Manhole (Sump, or Dry Well) System includes an inlet pipe, a sedimentation manhole, and one or more infiltration shafts with connecting pipes. Use of Infiltration Shaft will be limited by hydro- a) Locate infiltration trench at least 3m geotechnical conditions in much of GVRD. from any building, 1.5m from Limitations of Infiltration Trench or Soakaway Manholes: property lines, and 6m from adjacent a) To avoid groundwater pollution, do not direct un-treated polluted runoff to Infiltration Trench or Shaft: infiltration facilities (or as recommended by a geotechnical ▪ Direct clean runoff (roof, non-automobile paving) to Infiltration Trench or Shaft. engineer). ▪ For polluted runoff (roads > 1000 vehicles / day, parking areas, other pollution sources), provide upstream source control for pollutant reduction prior to release to Infiltration Trench or Shaft. b) Sump: Provide a lid for periodic b) Use infiltration trench or shaft only in areas with footing drains. inspection and cleanout. Include a 1. Grass or Other Planting T-inlet pipe to trap oils, sediments 2. Finish Grade and debris. 3. Growing Medium Backfill 4. 100mm Dia PVC DR28 Perforated 19 c) Infiltration Trench: installation of Pipe distribution pipe and bottom of 5. Light Non-woven Polyester drainrock to be level. If more than Geotextile c/w Min. 400mm Laps one section of infiltration trench is 9 1 required, design so that underground 6. 50mm Drain Rock or Rock of water is temporarily ‘ponded’ in each Equal Porosity infiltration section.
    [Show full text]